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A truck drives past a wind farm in Xinjiang, China.

Wind Could Provide 26% of China's Electricity by 2030

Last month Energywise argued that the primary reason Chinese wind farms underperform versus their U.S.-based counterparts is that China’s grid operators deliberately favor operation of coal-fired power plants. Such curtailment of wind power has both economic and technical roots, and it has raised serious questions about whether China can rely on an expanding role for wind energy. New research published today appears to put those concerns to rest, arguing that wind power in China should still grow dramatically. 

The report today in the journal Nature Energy projects that wind energy could affordably meet over one-quarter of China's projected 2030 electricity demand—up from just 3.3 percent of demand last year.

In fact the researchers, from MIT and Tsinghua University, project that modest improvements to the flexibility of China’s grid would enable wind power to grow a further 17 percent. That, they argue, means that China's non-fossil resources could grow well beyond the 20 percent level that China pledged to achieve under the Paris Climate Agreement.

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Perovskite solar cells made with vacuum-flash that surpass 20% efficiency.

Bigger and Better Perovskite Solar Cells

Solar cells based on crystals known as perovskites have advanced by leaps and bounds in recent years. Now scientists have found a way to increase perovskite solar cell size while maintaining the device’s high conversion efficiencies.

In the span of less than a decade, the conversion efficiency of perovskite solar cells has grown from 3.8 to 22.1 percent, an unprecedented rise in the field of photovoltaics. Such devices are also appealing because they are much cheaper to make than the silicon wafers used in conventional solar cells.

However, a major drawback of high-efficiency perovskite solar cells is how small they generally are, ranging from 0.04 to 0.2 square centimeters. Currently, the best conversion efficiency of a perovskite solar cell larger than 1 square centimeter is 15.6 percent.

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Modi and Obama Backstop Indian and Global Climate Action

The leaders of the world’s two biggest democracies—the U.S. and India—pledged at a White House meeting yesterday to complete their countries’ ratification of the Paris climate agreement by the end of 2016—a move that would bring the treaty into force before President Barack Obama leaves office. Obama and Prime Minister Nahendra Modi also announced specific actions on energy and climate in a joint statement, including: 

  • Initiation of preparatory work on a 6-reactor, 6.6-gigawatt nuclear power complex in India to be built by Westinghouse Electric, Toshiba Corp.’s U.S.–based nuclear engineering subsidiary.
  • A resolution to jointly broker an international agreement by the end of this year on the phaseout of hydrofluorocarbon (HFC) refrigerants, which are potent greenhouse gases.
  • New financing programs to catalyze renewable energy investments in India.

Phasing out HFCs could take a big bite out of projected global climate change this century, according to Andrew Light, a former advisor to U.S. Department of State on climate change policy and India and a fellow with the Washington, D.C.–based World Resources Institute. HFCs warm Earth’s atmosphere thousands of times more, molecule-for-molecule than CO2. Light says amending the Montreal Protocol to end their use by 2030 could, “avoid half a degree Celsius of warming by the end of the century.”

Reactor construction by Westinghouse, meanwhile, would culminate years of work to bring to India Western nuclear technology and financing (first approved for India by the U.S. Congress in 2008). The joint statement said engineering and site design for six AP1000 reactors would start “immediately” in the state of Andhra Pradesh. Obama and Modi set a June 2017 deadline for the U.S. Export-Import Bank to finalize a financing package. 

Nuclear remains a long road for India, however. India has been trying to grow its nuclear power sector since the 1950s, and currently has just 5 GW of capacity generating about 3 percent of the country’s power. Reactor projects can take a decade to complete. Light at WRI says it would take a “huge acceleration in construction” for nuclear power plants to meaningfully contribute to India’s power supply by 2030. Plus, adds Light, “costs have to make sense.”

Solar is now India’s energy source to beat on both cost and speed. Solar installations doubled last year and could double again this year. By 2020 India’s solar farms could be generating more gigawatt-hours of energy than the nuclear sector.

Much of the credit goes to the ambition of Modi, who has championed rural electrification and renewables since his election in 2014. Under Modi, reverse auctions and other supportive policies have cut solar energy costs to below 5 rupees (7.5 U.S. cents) per kilowatt-hour—lower than India’s average wholesale power rate. Indian energy minister Piyush Goyal recently stated that solar farms are cheaper than building new coal-fired power plants

Modi pledged in 2014 to boost India’s non-hydro renewable power capacity to 175 GW by 2022, including 60 GW of utility-scale solar farms and 40 GW of rooftop solar. At the time many experts called those goals wildly ambitious, but an increasing number express confidence that the utility-scale solar goal  at least is achievable. 

India will meet its 12 GW goal for the current fiscal year (which ends in March 2017), predicts Ajay Mathur, director general for The Energy and Resources Institute (TERI), a New Delhi–based NGO. “The spadework for that capacity is already done,” says Mathur, noting that government auctions have secured 15-GW worth of commitments.

What India needs most to sustain its renewable energy upswing, says Mathur, is access to cheap capital. Cheaper capital is one reason why reverse auctions elsewhere are yielding unsubsidized utility-scale solar bids twice as cheap as India’s.  WRI’s Light agrees: “The absolute key for India to hit its 2022 targets is cost of capital and finance.”  

Investment in non-hydro renewables in India rose 22 percent last year to US $10.2 billion, according to the United Nations Environment Programme. But that sum is dwarfed by the $102.9 billion that China invested. 

Modi and Obama’s meeting produced two renewable energy finance programs that could help. They appear small, but White House spokesman Brian Deese told reporters yesterday that they could facilitate much larger infusions of private and institutional capital. 

The Center for American Progress’ ClimateProgress blog, citing Deese, writes that a new $20-million U.S.–India Clean Energy Finance initiative will provide early-stage “risk capital” intended to mobilize up to $400 million in private capital by 2020. Another $40-million fund targeted primarily to microgrid projects in unelectrified villages, the U.S.–India Catalytic Solar Finance Program, promises to catalyze projects worth up to $1 billion.

Speaking of unelectrified villages, Modi’s government claims to be crushing his promise to give all citizens access to electricity by 2022. The International Energy Agency reported last year that 240 million people in India lack access to electricity, and by the Indian government’s count there were 18,452 villages lacking grid connections in April 2015.

But the number of powerless villages is in free-fall according to the government’s online electrification dashboard. It claims that power grid extensions have already electrified over 7,000 villages since last April, while microgrids have electrified another 558 villages.

An artist's rendering of EMBR Labs' thermoelectric wearable by Italian designer Niccolo Casas.

Wristify: Thermoelectric Wearable Would Reduce Energy Consumption

Last week Computex, the largest ICT trade show in Asia, was accompanied by record breaking heat (38.7ºC). So it should be no surprise that Wristify, a thermoelectric bracelet, was popular with visitors to the Taipei show.

Wristify, invented by MIT startup EMBR Labs, works because the wrist is rich with blood-flow, so the cold provides  quick relief. Similarly, it could also rapidly warm up a shivering skirt-wearing lady (your reporter) who’d been in an air-conditioned room for hours.

“… anytime you’re feeling too hot, too cold, stressed, or anything like that, you can basically control the sensation that you have on your skin and that can produce the overall effective, feeling better,” says co-founder David Cohen-Tanugi. 

The watch-shaped prototype wearable is manually controlled, letting the user adjust the temperature to their preferred level.  The team is adding intelligence so that a future product will be able to automatically adapt, according to Cohen-Tanugi. And the company is in the final preparations for a public launch of product pre-orders, which should happen by the end of September, he says.

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A device combines a silicon solar cell with a triboelectric generator that can harvest wind energy.

Solar and Wind Energy From the Same Device

A device that can simultaneously harvest energy from both the sun and wind might one day help generate power for "smart cities," researchers say.

Cities are growing smarter as networks of electronics help them monitor and control infrastructure and services. Ideally, these devices would be powered by renewable energy sources such as the sun and wind. Solar energy can come from rooftops and into even windows. However, large amounts of wind energy often gets wasted in cities—conventional wind turbines are usually not suited to urban areas because of their size.

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A wind turbine in China.

Why China's Wind Energy Underperforms

China accounted for 36 percent of global investment in renewable energy last year, pouring $102.9 billion into non-hydro renewables such as wind and solar power. The country is a laggard, however, in maximizing return on renewable energy dollars, especially for wind power. China closed out 2015 with nearly twice the installed wind power capacity of the U.S., yet last year it generated less wind energy.

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Perovskites Key to New Type of Hydrogen Fuel Cell

Crystals known as perovskites promise to revolutionize solar cells. Now researchers have found that they could improve fuel cells as well.

Fuel cells convert the chemical energy stored in fuels such as hydrogen into electricity. They do so by reacting the fuel with oxygen or another oxidizing agent that can strip electrons from the fuel. An electrolyte—commonly a polymer or ceramic—interposed between the fuel and oxidizer helps shuttle ions within the fuel cell.

Fuel cells are typically more efficient and environmentally friendly than heat engines, such as the internal combustion engines that usually power cars. However, fuel cells are often limited by how well their electrolytes can prevent electrons from leaking through them at the interface where the fuel and the oxidizing agent meet. Such electron conduction not only reduces fuel cell power output, but it can also lead to catastrophic fractures in the electrolyte.

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Plexiglass Gel Boosts Nanowire Battery Lifespan

A new battery material based on nanowires that can be recharged hundreds of thousands of times, could lead to commercial batteries for smartphones, laptops, appliances, cars, and spacecraft that have greatly enhanced lifespans, researchers say.

Scientists have long sought to create batteries using nanowires—strands only nanometers, or billionths of a meter, wide. Their tremendous surface area when compared with their volume makes them spectacular at storing and transferring electrical charge.

“Nanowires enable battery technology with higher power; you're able to get more current out of a battery the same size as [today’s] batteries, and make batteries smaller and get the same performance out of them as [the ones that are commercially available],” says Reginald Penner, an electrochemist at the University of California, Irvine.

The one drawback of nanowires has been their fragility, Penner says. Their thinness increases their susceptibility to dissolving and fragmenting under repeated cycles of discharging and recharging.

But now, Penner and his colleagues have developed a way to counteract that fragility. The researchers coated gold nanowires in manganese dioxide shells and formed an electrode by encasing hundreds of these nanowires together in a gel made from the same molecule found in acrylic glass. “The gel has the consistency of peanut butter,” Penner says. The scientists detailed their findings in 20 April online edition of the journal Energy Letters.

In experiments, the scientists cycled their electrode on and off up to 200,000 times over the course of three months without detecting any loss of energy storage capacity or power and without fracturing any nanowires. Typically, nanowire-based battery materials die after 7,000 or so cycles at the most, the researchers say. “It's surprising that such a simple change can trigger such a profound change in cycle stability,” Penner says.

The researchers suspect that the highly viscous and elastic acrylic glass plasticizes the manganese oxide shell, granting it flexibility and preventing it from cracking. A control sample of gold and manganese nanowires without the acrylic glass lasted only about 8,000 cycles.

Future research will explore if using a gel electrolyte can enhance other kinds of nanowires, Penner says. Subsequent work can also investigate other kinds of gels, and determine what effects will result from modifying the viscosity and other properties of the gels.

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Kyushu Earthquake Swarm Raises Concerns Over Nuclear Plant Safety

The populous island of Kyushu in southwest Japan has been shaken by hundreds of earthquakes and aftershocks over the past eight days, and there is no immediate end in sight to Mother Nature’s upheavals.

The tremors have impacted manufacturing for some companies in the auto and electronics industries, while concerns are growing over the safety of Japan’s two active nuclear reactors (the only two presently online), which are located about 120 km south of where the main shaking is occurring.

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